Electrical protective device.



O. A. ROLFE.

ELECTRICAL PROTECTIVE DEVICE.

APPLIOATION FILED DEG.29,1903.

Patented May 4, 1909.

jez/enwr: flzarlca (-9 W09?! UNITED STATES PATENT OFFICE.

CHARLES A. ROLFE, OF ADRIAN, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS, TO ROLFE ELECTRIC 00., OF ROCHJLSTER, NEW YORK, A CORPORATION U! M'LW YUllli.

ELECTRICAL PROTECT]. V'E DE VICE.

To all whom it may concern:

Be it known that I, CHARLES A. ROLFE, a

citizen of the United States, residing at useful Improvement in Electrical Protective Devices, of which the following is a full, clear,

' tecting low tension circuits concise, and exact description, reference being bad to the accompanying drawings, forming a part of this specification.

My invention relates to devices for prosuch as telephone, fire-alarm andv the like, from damage or injury b the unduly strong currents coming from c ectric light, trolley and The principal object of the invention is to provide a simple, ractical and inexpensive orm of device of t is kind which will not require repair or replacement after 0 oration.

In the accompanying drawing, Flgure 1 is a side elevation of a rotective device of the class mentioned, em odying my invention; Fig. 2 is a bottom view of the heat cartridge thereof; Fig. 3 is a longitudinal section taken on line 33 in Fig. 2, but with the device operated and showing also the supporting members for the heat cartridge; Fig. 4 is a cross .section taken on line 44 in Fig. 2: Figs. 5 and Gare respectively a side elevation and a lon 'tudinal section of a portion of a modified orm of device; Fig. 7 is a section taken on line'7-7 in Fig.5.

Referring first to the device shown in Figs. 1 to 4 inclusive, A represents a suitable insu'lating base which can be made of any desired form and material such as porcelain, wood or the like. U on this base are mount .ed two s rings 1 an 2 which rise from theso an support at their ends a heat cartridge B. e springs 1 and 2 tend to spring outwardly or separate from one another but are held in restraint by the heat cartridge. The latter consists of two pieces 3, 3', of insulation preferably ebonitc, a coupin' 4 connecting said pieces of insulation an to such end made with cup-shaped ends, and terminals 5,.5 at the outer ends of the insulation pieces 3, 3; the terminals 5, 5 be mg also cup-shaped to embrace the ends of the pieces of insulation, and having heads 6, 6 adapted to be engaged b the forked ends of t e springs I and 2. Tlie coupling 4 is made with a central slot or cavity 7, and in this a lever 8 is pivoted-: Springs 9, 9, are

power circuits.

Specificatibn of Letters Patent.

Application filed December 29, 1803.

Patented May 4, 1909.

Serial No. 187.041.

mounted u on the pieces 3, 3 of insulation, and exten over so as to engage the top or head of the lever 8 which is for such purpose provided with a notch 10. Each piece of insulation 3, 3'is provided with a graphite stick or pencil 11 whose u iper ends come in contact with the flanges oi the coupling 4 as shown in Fig. 3, and whose lower ends are engaged by springs 12, 12 which are extended and secured to the terminals 5, 5. A small quantity of solder 13 is placed in the cavity in the coupling 4 so as tozhold the lever 8 normally in the position in which it may be )laced. This device operates as follows. lnder normal conditions it will be arranged as shown in Fig. l, with the spring, 1 in engagement with.the lower end of the lever 8 and the sprin 2 which is forked, in engagement with thehead 6 of one of the terminals So long as the conditions ofthc circuit are nor mal, the device will remain in this condition, with the circuit closed through it by way of the head 5 engaging the s ring 2 the spring 1 2 connected with said hea the graphite stick 11 connected with said spring, the coupling 4, the lever 8, and the spring 1. When an unduly strong current passes through the circuit, the graphite 11 is heated, thereby causing the melting of the solder i3 and re ieasing the lever b, which when relcnsed is thrown outwardly by the spring I, with the result that the spring 1 passes beyond the end of the lever and becomes disengaged therefrom, thereby opening the circuit as shown in Fig. 3. When this has been done, the lever 8 assumes the position shoun in dotted lines in Fig. 1 and in full lines in Fig. 3, and is resoldercd in that position by the cooling of the solder 13%. When the circuit is to be restored to operative condition aftci' the removal of the trouble, ihc hcat cartridge B is lifted so that it becomes disengaged from the spring 2, and is reversed in position; that is, the ends arc-interchanged so that the terminal 5 formcrly not in engagement with the spring 2, is piaced in engug'cmcnt therewith. The lever 8 thus is placed in the same position in which it was origins-ll that is, inclined toward the spring 2, ant its lower end is engaged with the spring 1, there-h placing the device in substantially its original condition, ready for another operation.

The device shown in Fi s. 5, 6 and 7 coinprises two springs 13 an 14 which are untill loo

derstood to be similar to the springs 1 and 2 of the above described device, except that both the springs 13 and 14 are forked, and are also understood to be extended down to a suitable insulating base which is not shown. These sgrings 13 and 14 sup ort a heat cartridge which, consists o? a c lindrical grisphite stick or pencil 15 prov'i ed at its en s with terminals 16 and 17. both of which are made cup-shaped so as to embrace the ends of the graphite, and one of which, 16, is provided with a headlS to engage the sprin 14. These terminals 16 and 17 are securei to the graphite stick 15 by pins 19, 19 passin throng t e graphite stick, and also by hard solder which makes fast the joints between the terminals and graphite stick. The terminal 17 is slotted at its outer end, as shown in Fig. 7, and a trigger 20 is pivoted between the forks 21, 21 formed by the slot in said terminal. A small quantity of solder 22 is confined between the forks 21, 21 so as to hold the trigger 20 firmly in any position to which it may be adjusted'when said solder is cold. The operation of the device is as follows. When the circuit is in normal condition the device is arranged as shown in Fig. 5, the spring 13 being held in position by the trigger 20 which is inclined with its lower end inwardly. So long as the current in the circuit is normal the device remains in this condition, the current passin between the springs 13 and 14 by way of t e trigger 20, terminals 16 and 17, and graphite stick 15. When, however, the current becomes unduly strong, the raphite stick 15 is heated, thereby causing tie solder 22 to become softened or melted, with the result that the trigger 20 is released and the spring 13 is allowed to sprin or move outwardly. When this occurs the trigger 20 is shifted or swung about from the position shown in Fig. 5 to that shown in Fig. 6 and the spring 13 is allowed to free itself from saidtrigger as shown in Fig. 6, thereby opening the cir cuit. The solder 22 in cooling hardcns about the trigger 20 thereby holding the same in the position shown in Fig. 6. To restore the device to operative condition it is simply necessary to reverse the heat cartridge B by turning it about its lon itudinal axis 180 degrees, or in other wor s by turning it so that its upper and lower sides are changed in position. lhe trigger 20 then comes into position with its lower end inwardly or nearest the sprin 14 and the spring 13 is enga ed therewith as before.

mm the foregoin it will be seen that the device can be restore to condition for operation withont repair or re lacement of other parts, and this IS accomp ished merely by reversing'the position of the heat cartridge in its sup )orting members. Provision for this mversa can be nade by constructing the heat cartridge in various ways, two of which are shown herein, the first one comprising pri'tctically a doubic cartridge with a single ever or trigger, and the second a single cartridge with a double lever or trigger; in any event the operated part,that is the lever or trigger,----o the cartridge is not moved back or restored to any normal position in the cartridge but is rcsoldered in the ,position to which it is moved by operation, and then the cartridge itself is reversed in order to place the device in condition for a subsequent operation.

lt will be understood that the two foregoing arrangements are merely exemplary of many forms of device which can be constructed upon this principle, and that I do not therefore wish to confine myself merely claim specifically the double trigger device' shown in Fi s. 5, 6 and7.

What I claim is 1. In apparatus of the class s ecified, an excess current operated device a apted to be changed in position and provided with means whereby one operation places the device in condition for another operation'in a changed position. i

2. .ln apparatus of the class specified, a reversible excess current operated device provided with means whereby one operation places said device in condition for another operation in a reversed position, substan tially as described.

3. In apparatus of the class s ecified, a reversible heat cartridge provider with means whereby one operation places said cartridge in condition for operation in a reversed position, substantially as described. Y

4. In apparatus of the class specified, the combination of circuit controlling means and an excess current operated device provided with means for engaging said circuit-controlling means, said engaging means being adapted to engage the circuit controlling means in different positions of the excess operated device, and the excess operated device beinv adapted to be placed by one operation in condition for another operation in a diti'erent position, substantially as described.

5. In apparatus of the class s ecified, the combination with circuit controlling springs, of an excess current operated device rovided with means for engaging said s rings, and made removable therefrom and a apted means whereby its operation by said springs in one p'osition places it in condition for an other operation in a'reversed position.

7. In apparatus of the class specified, the combination with a pair of circuit controlling springs, of a heat cartridge comprising means for engagingone of said springs with the cartridge in reversed positions, a movable part adapted to engage the other spring with the cartridge in reversed ositions, material affected by heat for holding said movable part against movement, and means for developing heat sufiicient to affect said material and permit movement of'said movable part upon the passage of an unduly strong current, substantially as described.

8. In apparatus of the class specified,'the combination with a pair of circuit controlling springs, of a heat cartridge engaging said springs and holding the same in restraint, said cartridge comprising means for engaging one of said sp'rihgswith the cartridge in re-. v'ersed positions, a pivoted lever adapted to engage the other spring with the cartridge in reversed positions, softenable materiel associated with said lever to hold the same nor- Inally against movement, and meansior developing suflicient heat to soften said material, and thereby release said pivoted lever upon the passage of an unduly strong (orrcnt. 4

9. In apparatus of the class specified, the combination with apair of circuit controlling springs, of a heat rartridgc engaging said springs and holding the same in restraint, said cartridge comprising means for engaging one of said springs with the cartridge in. reverscd positions, a pivoted lever adapted to engage the other spring with the cartridge in reversed )ositions, a small quantity of solder holding t c said lover normally against movement, and means for developing heat to melt or soften said solder and thereby release said lover upon the passage of an unduly strong current.

H2. in apparatus of the class SPfli'lllld, a hunt cartridge romprising means for (fl'lg'itlk inga pair of rir euit controlling springs with tho rartridgr in different positions, and nu-ans \vhrrohy opvration in one position of thicnririd, ro, plants the smne in condition for another opvration in a dill'r-ront positior.

heat cartridge com )rising means for engaging a circuit controlling spring with the cartridge in different positions, a movable part 'for engaging another spring, said part being arranged and adapted to be moved by said other spring in operation, to plaqe it in condition to restrain said spring with the eartridge in a diil'erent position, material normally hard but adapted to be softened by heat, for holding said part normall against movement, and. means for developing heat to soften said material on the passage of an unscribed.

12. In apparatus of the class-s )ecifird, a heat rnrtridgc ooinn ising means 'ior engaging 'a iii-nut. rontrolling spring with the cartridgc in reversed positions, a pivoted lever adapted to engage another circuit (:OIltI'Olling spring, said lever being arranged in its diiiurvi'it. positions to hold said spring in re streint with the cartridge in reversed positions, a small quantit of solder for holding said lever normally against l'novement, and means .for developing heat to soften said solder on the passage of'an nndulj strong current, supstantiall; as dcseribed.

13. In apparatus of the class spe-;.ified, the combination with a pair of (,iloult controlsprings and holding the same in restraint, said -artridgc oinprislng a pair of nntallr;

one ofsaid springs, a devise for engaging tho other spring, loizatcd between said heads, and means vlui-rch said, devi is is hold normally against move-limit but is permitted to move on the passage of an undul, strong euircnt, substantiz as (l 's'-rihcd.

14. in apparatus oi the iiass spc't'llhul, the aonihination with .1 pair of line spl lllgfiplll a heat :n'tridgo engaging said springs nnd holding the same in restraint, said cartridgo romprising :2 pair ofidrri is for engaging our of said springs, a d vi-ro for lngnging the othrr sprinir, lo-utrd bctwrcn said ,pc.ir of doviwvs, a small quantity of material nornmill hard but so'i trnahlc upon a moderate cxorss of heat, and a heat concentrating desage of an unduly strong current, said internn-diate devise liping adapted to be moved by said lino spring into position to he rcin 1 gagrd thereby when the device is turned end for and, substantially as described.

1-"). ln apparatus of the class spcoificd, the combination uith a pair of circuit ontrolling springs, of n. hrnt rartridgo engaging said springs and holding the same in restraint, said artridg oolnprising a pair of separated terminals r-aoh adapted to engage one of said springs, a pivoted lovor located hetwcensaid H. In apparatus of the "lass s mcilicd, a 1 other lincspring, a small quantity of solder duly strong current, substantially as dew terminals or heads each adapted for engaging vise for softening said material on the pas tafilllllilltlh and adapted to lie-engaged by the ling springs, of ahe at oartridge engaging said normally holding said lever against movement, and ineans for concentrating heat to soften said solder on the passage of an unduiy strong current, substantially as described.

16. In apparatus of the class specified the combination of a pair of circuit controlling springs 1 and 2, of a heat cartrid e comprising terminals -6, 6, each adapte 'to ena pair of separated terminals, a movable deheat cartri vice located between said terminals and adapted for engaging a line spring, and,

means whereby said device is held normally against movement durin the passage of a normal current, but is released and permit ted to move on the passage of an excess current, substantially as described.

18. In apparatus of the class specified, a.

ge comprising a pair of separated terminals, a. pivoted device, located between said terminals, means for holding said device normally against movement, an

means whereby said holding means is affected to release the deviceon the passage of an unduly strong current, substantially as described I 19. In apparatus of the class specified, a heat cartridge, comprisin a pair of separated terminals 6, 6, a pivoted lever 8 located between said terminals, a small uantity of sol'tenable material normally hdlding said lever against movement, andrncans for concentrating heat on the passage of an unduly strong current to melt or soften said material, substantially as described.

20. In apparatus of the class specified, a

solder, sub' "solder joint reversible heat cartridge having provisions for automatically resoldering itself;

2 1 A protector for electrical circuits, having a heat cartridge having means whereby it can be reversed in position in the protector, and also having rovisions for automatically resoldering itse f after 0 oration,

22. Aprotector for electrics circuits, havin a heat cartridge provided with a' rnovab e member, and also with a solder joint normally holding said member. against movement, the cartridge and protector having provisions for the engagement of the cartridge in reversed positions with its mo vable member in different positions, and also havin provisions whereby saidmember is with the cartridge in a reversed position, the

intact after operation, whereby said member is automatically resoldered after operation ent position in the cartri 23. A'heat cartridge for, electrical circuit protectors provided with engaging devices at its opposite ends an between its ends, the cartri ge having provisions ,for automatically resoldering sa id intermediate engaging device after operation.- H :i

24. In apparatus of the class s eclfied, la solder-joint reversible heat cartri 'ge', having provisions for automatically resoldering itself in operative condition.

25.'In apparatus of the class 3 ecified, a reversible so der-joint heat cartri ge having provisions for automatically resoldering itself after operation.

In witness whereof, I hereunto subscribe my name this November 16th, A. 1)., 1903. CHARLES A. ROLFE.

Witnesses A. MILLER BELFIELD,

I. C. LEE.

place by operation in position for operation in condition for another 0 oration in a differsolder joint of said movable member being, 

